In drilling boreholes for the production of hydrocarbons, it is necessary to install a casing which extends from the surface of the earth to an elevation located downhole in a borehole. The annulus between the borehole wall and the exterior of the casing must be completely filled with cement, thereby preventing communication between various strata through which the borehole extends.
There are cementing tools known to those skilled in the art which can be manipulated to provide bypass from a medial portion of the casing string directly into the borehole annulus. These tools are expensive, complex in design, and often must be drilled after the cementing operation has been completed.
It is therefore desirable to have made available a cementing tool which is simple in design, positive in operation, and which is fabricated in such a way that there is no need to drill a passageway through the interior of the tool after the cementing operation has been completed.